blue85305

i have a 350 with the 882 heads i didnt build the engine so i dont know about the pistons but i have a set of 416 heads laying around, would i gain much power by swapping on the 416s or would it be a waste of money?

five7kid

iTrader: (14)

Just putting the 416's on would only raise power due to an increase in compression. That may be adequate depending upon the rest of your package (cam, induction, exhaust, etc.). But, 416's with 1.94" intake valves (1.60" exhaust optional), good valve springs, pinned or screw-in rocker studs, would be capable of much, much more (depending upon the rest of our package).

Sonix

iTrader: (1)

sounds like a familiar combo

yes, you'll gain compression, and probably a bit of flow. when you go to swap them on, check what pistons are on there, if stock dished style, you're golden. if they are aftermarket flat tops, then you'll need premium fuel after, but you'll still be ok.

chesterfield

I'd say 416s would be a bad move.And in defense of the 882s I'll post this link again.

flow-2

882s outflowed aluminum Corvette L98 heads. If you're talking a straight swap all you'll get is higher compression. I don't think 416s outflow 113 corvette heads. (now don't get me wrong. I'm not suggesting anyone go out and buy 882s.) But you've already got them on your car. According to David Vizard, raising your compression ratio one point is good for 2% hp increase. Two points, 3.7%.

Doom86

i guess those flow numbers are great if you believe them.

a lot of people, performance enthusist, engine builders, racers and what not say they are garbage. People who have USED them, worked on them, and swaped on other castings and made much more power say they are trash.

given those flow numbers you could make 350hp all day long on a mild sbc. if this was true you'd be reading threads all over the place about swaping them on and running 12's.

while we're passing on internet wisdom, i've seen a engine dyno where a worked over set of 882's with "$1200" of machining and porting didnt even make 300fwhp on a full bolt-on 350! let alone stock castings with the narrow runners and huge chambers.

84z28350

who the heck is going to believe some flow numbers on a freebie webpage?

Even the flow numbers used by desktop dyno and digital dyno are not from true stock 882 castings they were from worked heads. Like the poster above said, if their so great why isnt everyone using them?


I would personally go with the 416s any day, mostly because of their small chamber and with some minor machining will stomp worked 882s!

Fast355

iTrader: (2)

https://www.thirdgen.org/forums/tbi/...+heads+350+tbi

chesterfield

I wouldn't dismiss any information just because its a freebie website like TGO.

"This aluminum head(113) was used on the Corvette TPI engines from the mid-Eighties until the LT-1 1992 motors were introduced. The 882-iron head out-flowed this head across the board."(chevyhigh performance)

Car Craft's Head Flow Database

Here's an article where Hotrod Magazine got 300hp out of unported 882s.
Easy Power Gains


Here's alink to flow numbers for ported 416s. Note they're lower than unported 882s at CarCraft
https://www.thirdgen.org/forums/tech...w-numbers.html
05 29.4 24.6
.10 57.4 48.3
.15 88.3 75.0
.20 122.1 100.2
.25 152.2 113.9
.30 172.9 128.7
.35 188.7 139.4
.40 201.8 147.3
.45 213.3 152.2
.50 217.8 159.2
.55 220.7 161.2


I don't have any reason to believe anyone is lying about 882 flow. blue85305 asked if swapping 882s for 416s was worth it. I'm assuming we're talking about stock heads. Are you all saying its bad advice to leave the 882s on there?

Fast355

iTrader: (2)

882, 993, 624 etc, ALL flow less than stock 416s, 081s, or 601s. Just the cold hard facts, yes I have flowed more sets than I care to mention. 193s will outflow 882s! I pulled a pair of 882s of my 1980 chevy truck 350. I put on a pair of stock 193s, it pulls much harder from idle-5,500+.

Yank the 882s off, slap on the 416s and you will be happy. You will be happier if you work the 416s. Flow is not everything, swirl, quench, compression, chamber, are just part of it.

Sonix

iTrader: (1)

wait, what?
I read that first link, it showed different flow tested heads, the 882's flowed a max of 207 cfm at .5", so that stuck in my mind... The chart posted showing 416 heads showed a max of 217 at .5".... Am I missing something?

yea, another thread right now has someone that pointed out that 113 heads were some of the poorest flowing heads out there... but that's beside the point right now...

urbanhunter44

iTrader: (3)

imo the 416 heads, ported and polished and cut for bigger valves can be some nice little street rod heads indeed

chesterfield

Sonix, you're right I apologize. I was focused on the lower lift numbers which favor the unported 882s over the ported 416s.

Does anyone have flow numbers for unported 416s. All we have is "should be the same as...."

Stekman

I say port the 416's (DIY isn't hard at all, no, really, it isn't!), get them worked over all nice-like, then swap. I did on an 85 Caprice and never regretted it - and that's a 6,000,000 lb boat to boot.

Doom86

chesterfield, they are in the business of advertising. now they wouldnt sell many bolt ons for these companies if they showed you what really happens. That engine probably made 180HP, if it was lucky, in stock trim. They have it making 225-230 hp on the "stock" dyno, they lost all credibility right there.

now people who are not in the business of selling you anything, but helping you, tell you they are junk and its questioned.

you can compare flow numbers against those fantasy 882 numbers all day and it still doesnt mean anything. you gotta have all the facts straight for a fair comparison. even comparing flow numbers between two different flow benches is generally a waste of time, they dont all give the same results.

when i got my 350 for the rebuild. i unbolted the 882's and examined them, found everything i've heard about their poor design to be true and i tossed them in the "junk" pile to be taken to the recycling center. tiny runners and huge chambers are certainly not what you want for performance. id be amazed if they had even 150cc intake runners.

Doom86

according to those "stock" flow numbers for the 882's this is what desktop dyno predicts for a power curve..

this is; small tube headers w/ mufflers, dual plane intake, xe268 cam and 750cfm carb, and generous 9:0 compression. in other words, further room for improvement with better "bolt ons". Now wouldnt we all have some 882's on our engines if this is how they performed in a rather mild setup?

84z28350

Did none of you guys read the fine print in CHP's mag when they flowed those 882's???

THEY WERE WORKED! NOT STOCK CASTINGS!!!!!

So with that said (again) the numbers that desktop dyno and digital dyno use which they got from CHP are not stock flow numbers. You can believe DD all you want but throw those 882s on a engine with the same specs and see what it dynos at...


As for those 'ported' 416s flowing less than the 'stock' (worked...) 882s, No disrespect to the guy that ported them but it could have been a sh!tty port job. Someone else's porting may get alot more flow!

Doom86

I certainly dont believe the DD numbers, thats why i posted it (maybe you read me wrong). There is no way they make that kinda of power, stock, on a mild 350.. otherwise we'd all be running to the junkyards tomorow to jump into the piles of 993's and 882's that they have for the scrapper.

chesterfield

84z28350, could you show me where chp put the fine print? In this article they refer to it as "stock iron 882"

Flow Power


Some people are running to the junkyards apparently.I have no reason to believe they are making this up. I have no reason to disbelieve the dyno test of 364hp on this page. Or any of the other combos with 882s.

SMALL BLOCK


I have no reason to believe this guy is lying about his dyno of 274hp.

AllChevyNova.com

Fast355

iTrader: (2)

https://www.thirdgen.org/forums/tech...416+heads+flow

https://www.thirdgen.org/forums/tech...w-numbers.html

https://www.thirdgen.org/forums/tech...w-numbers.html

https://www.thirdgen.org/forums/tech...601-heads.html

https://www.thirdgen.org/forums/carb...our-q-jet.html

https://www.thirdgen.org/forums/tech...-pictures.html

chesterfield

fast355,
Was your last post directed to the question of our comparison of unported 416s vs unported 882s, or was it just for general information? There were no cold hard facts regarding stock flow numbers that I could see.

But back to your earlier post with this link:

https://www.thirdgen.org/forums/tbi/...+heads+350+tbi


350 roller cam fuel injected LO5 made 206 hp with 416s "just cleaned up the ports a bit and polished the chambers and installed some back cut lt1 valves on the exhaust sides"

1976 350 L82 4 bbl corvette motor came stock with 882s rated at 210 hp. no head work.
Are we closer to apples and apples comparison? Remember the question here. Is it worth it to swap 882s for 416s? I can only assume that we're talking stock for stock because we have no other information. So if someone asked me if they should replace their heads on their '76 corvette with heads that produce relatively the same power on a '91 caprice 9c1, I think it would be good advice to say no.

Fast355

iTrader: (2)

The last post was for general 305 head info.

206 HP at the wheels, not the crank. The old vettes were 210 FWHP with a 224/224 @ .050, .450/.460" lift cam, and the 882s used 2.02/1.60 valves on the L82s. His 416s have LT1 valves, very little work, and used the LT1 roller cam 205/207 @ .050, .447/.459" lift cam, and a TBI setup that could have used alot more tuning. The 700r4 eats more HP than the manual transmission that came in the vettes as well. 206 RWHP is around 250 FWHP, which blows the 210 of the 70s Vettes out of the water. I had an esentially stock (stock long block) 1984 305 converted to TBI that pulled 181 RWHP which is around 220 FWHP. Marine 305s used the same cam/heads as trucks with a less restrictive exhaust, better timing curves, and a less restrictive air intake (no filter just a backfire suppressor) and made 230 FWHP. I don't see your point.

Sonix

iTrader: (1)

haha, ok, now we're splitting hairs here.

Technically speaking, the 416 heads are a newer design then the older 882 castings, so should be a more advanced design.

I think a direct swap would barely be worth the effort it takes to swap them. But if you were to port the 416's, then put them on, you'd be MILES ahead. The beauty with that (as opposed to porting the 882's) is no vehicular downtime. Also the 416's higher compression favors the xe268 cam more.

chesterfield

no point

Doom86

i have to agree completely sonix.. this is going no-where.

we can get excited about guys with fully worked bolted on 406 sbc making 275hp, or understand that is nothing to boast about, a stock headed 305 sbc can do that. I'm sure the power curve favors the 406, but stall your 305 and you're nearly on the same page.

we can have a link war, spreading "internet wisdom", with guys who probably have never held either castings in their hands. or just save the grief and move on.

the truth is 95% of chevy heads cast in the last 50 years are garbage. Stock for Stock swapping is nearly pointless, unless you have a junkyard jewl sitting in wait. Neither 882 or 416 are that jewl. I wouldnt waste the money swapping nearly ANY stock head on a motor i expected to perform. Now take those 416's and have them cut for 1.94 intakes, with undercut valves and a 3-angle valve job slap them on and you'll make some great power over those smogger 882's.

blue85305, how does the car pull now? have you ever raced it? You already got a mild 350 with 882's. Rouge86 had a stock 416 (with the very poor stock valves) running low 13's on a milder 350 then you have now. do some searching and you'll find others too.

Sonix

iTrader: (1)

I think in mid to late '60s cars were rated with Gross HP, hence the high ratings. after '72 or whatever, it was net HP, which includes water pump, alternator, exhaust manifolds, etc. However it's all still flywheel HP, no car manufacturer has ever rated their motors at rear wheel HP. ('cept maybe the grand national, or other notoriously underrated motors ).

Either way, we're all learning here, and we can all agree stock for stock is almost a waste of effort turning wrenches, but ANY ported stock heads will help, and some of us believe ported 416s are a good way to go.

I think 57 had it right in the first response.

mw66nova

iTrader: (13)

just FYI, i have a set of 113 casting vette heads on my car with just a mild bowl blend (MILD) and a fresh 3angle valve job with 10.2:1 c/r and a crane powermax solid cam and i've gone 12.16@110mph rolling into the throttle so i didn't break the tires loose, once i get the rearend situated so i can really stomp on it out of the hole, i totally expect 11.8's/11.9's. i didn't touch the runners on either the intake or exhaust side. just a mild bowl blend.